Displaying publications 41 - 60 of 841 in total

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  1. Fulltext Understanding the NaCl-dependent behavior of hydrogen production of a marine bacterium, Vibrio tritonius
    Al-Saari N, Amada E, Matsumura Y, Tanaka M, Mino S, Sawabe T
    PeerJ, 2019;7:e6769.
    PMID: 31024772 DOI: 10.7717/peerj.6769
    Biohydrogen is one of the most suitable clean energy sources for sustaining a fossil fuel independent society. The use of both land and ocean bioresources as feedstocks show great potential in maximizing biohydrogen production, but sodium ion is one of the main obstacles in efficient bacterial biohydrogen production. Vibrio tritonius strain AM2 can perform efficient hydrogen production with a molar yield of 1.7 mol H2/mol mannitol, which corresponds to 85% theoretical molar yield of H2 production, under saline conditions. With a view to maximizing the hydrogen production using marine biomass, it is important to accumulate knowledge on the effects of salts on the hydrogen production kinetics. Here, we show the kinetics in batch hydrogen production of V. tritonius strain AM2 to investigate the response to various NaCl concentrations. The modified Han-Levenspiel model reveals that salt inhibition in hydrogen production using V. tritonius starts precisely at the point where 10.2 g/L of NaCl is added, and is critically inhibited at 46 g/L. NaCl concentration greatly affects the substrate consumption which in turn affects both growth and hydrogen production. The NaCl-dependent behavior of fermentative hydrogen production of V. tritonius compared to that of Escherichia coli JCM 1649 reveals the marine-adapted fermentative hydrogen production system in V. tritonius. V. tritonius AM2 is capable of producing hydrogen from seaweed carbohydrate under a wide range of NaCl concentrations (5 to 46 g/L). The optimal salt concentration producing the highest levels of hydrogen, optimal substrate consumption and highest molar hydrogen yield is at 10 g/L NaCl (1.0% (w/v)).
    Matched MeSH terms: Sodium; Sodium Chloride; Sodium Chloride, Dietary
  2. Fulltext Microwave-assisted Preparation of Cross-linked Gelatin-Paracetamol Matrices: Optimization Using the D-optimal Design
    Kuang TK, Kang YB, Segarra I, Kanwal U, Ahsan M, Bukhari NI
    Turk J Pharm Sci, 2021 04 20;18(2):167-175.
    PMID: 33902255 DOI: 10.4274/tjps.galenos.2020.48902
    Objectives: This study was conducted to assess the effect of microwave heating on the preparation of paracetamol cross-linked gelatin matrices by using the design of experiment (DoE) approach and explore the influence of the duration of microwave irradiation, the concentrations of crosslinker, and the amount of sodium bicarbonate (salt) on paracetamol release. These parameters were also compared with those of the matrices prepared via conventional heating.

    Materials and Methods: Twenty gel matrices were prepared with different durations of microwave irradiation, amounts of maize, and concentrations of sodium bicarbonate as suggested by Design Expert (DX®). The percentage drug release, the coefficient of variance (CV) in release, and the mean dissolution time (MDT) were the properties explored in the designed experimentation.

    Results: Target responses were dependent on microwave irradiation time, cross-linker amount, and salt concentration. Classical and microwave heating did not demonstrate statistically significant difference in modifying the percentage of drug released from the matrices. However, the CVs of microwave-assisted formulations were lower than those of the gel matrices prepared via classical heating. Thus, microwave heating produced lesser variations in drug release. The optimized gel matrices demonstrated that the observed percentage of drug release, CV, and MDT were within the prediction interval generated by DX®. The release mechanism of the matrix formulations followed the Peppas-Korsmeyer anomalous transport model.

    Conclusion: The DoE-supported microwave-assisted approach could be applied to optimize the critical factors of drug release with less variation.

    Matched MeSH terms: Sodium Chloride; Sodium Chloride, Dietary; Sodium Bicarbonate
  3. Fulltext Sodium intake among normotensive health staff assessed by 24-hour urinary excretion: a cross-sectional study
    Rashidah, A., Yeo, P.S., Noor Ani, A., Muhammad Fadhli, M.Y., Tahir, A., Feisul Idzwan, M., et al.
    Malays J Nutr, 2014;20(3):317-326.
    MyJurnal
    Introduction: High sodium consumption over an extended period of time has been associated with hypertension, stroke, cardiovascular disease, renal damage, and other adverse health effects. This study aimed to determine urinary sodium excretion and consequently estimate dietary sodium consumption among normotensive health staff in Malaysia. Methods: A cross-sectional study was conducted to acquire data on sodium excretion among normotensive Ministry of Health staff aged 20 - 56 years (mean age 35.08, SD 9.78) in 14 states and a research institute. Respondents were recruited using quota sampling. Data collection was conducted from December 2011 to February 2012. A single urine sample was collected over 24 hours for sodium concentrations and calculated as 95.0% of total daily sodium intake. Results: Among the 471 enrolled respondents, 445 (94.0%) provided complete information on socio-demography and urine samples. Mean urine sodium excretion was 142.0 mmol/day (SD 71.7), which is equivalent to 3429 mg sodium/day or 8.7 gm of salt intake (1.75 teaspoon, which exceeds the Malaysian recommendation of 2000 mg sodium/day by 1.7 times. About 79.0% (n=353) of respondents (88.0% male and 73.0% female) had daily sodium consumption that was above the recommendation. Excretion was significantly higher among males at 161.7 mmol/day (SD 78.1) (3726 mg sodium/day) than females, 125.3 mmolfday (SD 61.1) (2875 mg/day). There was a positive, low correlation between BMl and sodium intake (r=0.216, p
    Matched MeSH terms: Sodium; Sodium, Dietary; Sodium Chloride, Dietary
  4. Fulltext Optimization of culture conditions for Mpt64 synthetic gene expression in Escherichia coli BL21 (DE3) using surface response methodology
    Kusuma SAF, Parwati I, Rostinawati T, Yusuf M, Fadhlillah M, Ahyudanari RR, et al.
    Heliyon, 2019 Nov;5(11):e02741.
    PMID: 31844694 DOI: 10.1016/j.heliyon.2019.e02741
    MPT64 is a specific protein that is secreted by Mycobacterium tuberculosis complex (MTBC). The objective of this study was to obtain optimum culture conditions for MPT64 synthetic gene expression in Escherichia coli BL21 (DE3) by response surface methodology (RSM). The RSM was undertaken to optimize the culture conditions under different cultivation conditions (medium concentration, induction time and inducer concentration), designed by the factorial Box-Bhenken using Minitab 17 statistical software. From the randomized combination, 15 treatments and three center point repetitions were obtained. Furthermore, expression methods were carried out in the flask scale fermentation in accordance with the predetermined design. Then, the MPT64 protein in the cytoplasm of E. coli cell was isolated and characterized using sodium dodecyl sulfate polyacrilamide electrophoresis (SDS-PAGE) then quantified using the ImageJ program. The optimum conditions were two-fold medium concentration (tryptone 20 mg/mL, yeast extract 10 mg/mL, and sodium chloride 20 mg/mL), 5 h of induction time and 4 mM rhamnose. The average concentration of recombinant MPT64 at optimum conditions was 0.0392 mg/mL, higher than the predicted concentration of 0.0311 mg/mL. In conclusion, the relationship between the selected optimization parameters strongly influenced the level of MPT64 gene expression in E. coli BL21 (DE3).
    Matched MeSH terms: Sodium Chloride; Sodium Dodecyl Sulfate; Sodium Radioisotopes
  5. Fulltext Sodium content in sauces-a major contributor of sodium intake in Malaysia: a cross-sectional survey
    Shahar S, You YX, Zainuddin NS, Michael V, Ambak R, Haron H, et al.
    BMJ Open, 2019 05 27;9(5):e025068.
    PMID: 31133578 DOI: 10.1136/bmjopen-2018-025068
    OBJECTIVE: To investigate the sodium content in sauces sold in Malaysian supermarkets.

    METHODS: A cross-sectional market survey was conducted in 2017 of 233 sauces sold in Malaysian supermarkets. Information on the sodium content was collected from the product packaging and nutrient information panels of the sauces sold in the seven top supermarkets in the capital of Malaysia.

    RESULTS: Of the 233 sauces surveyed, 116 did not include sodium content information on the nutrient information panel (49.8%). Soy sauce (particularly sweet soy sauce) and ketchup (particularly chilli sauce) were found to be the highest number of products surveyed in the analysis (N=54 and N=48, respectively). The highest sodium content information was displayed by fish/prawn sauce (budu/cencalok) (5192±3228 mg/100 g) which was followed by the light/thin soy sauce (5116±2084 mg/100 g), and followed by salty soy sauce (4780±988 mg/100 g). The sodium content information of the imported sauces was higher compared with local products produced in Malaysia. However, for sweet soy sauce, the sodium content information of the local products was higher compared with the imported products. Of the 116 sauces which displayed information regarding their sodium content, only 18.2% of the salty soy sauce and 25% of the light/thin soy sauce were found to be below the 2017 Malaysian sodium guidelines. Furthermore, only 21.7% of chilli ketchup and no tomato ketchup were below the 2017 UK salt guidelines.

    CONCLUSIONS: Almost half of the sauces surveyed did not include sodium content information on the nutrient information panel. It is recommended that sodium content information is provided on all sauces sold in Malaysia. Also, manufacturers should be urged to reduce the sodium content level of their sauces to a minimum of 5%.

    Matched MeSH terms: Sodium; Sodium Chloride; Sodium Chloride, Dietary
  6. Fulltext Antimicrobial Efficacy of Fruit Peels Eco-Enzyme against Enterococcus Faecalis: An In Vitro Study
    Mavani HAK, Tew IM, Wong L, Yew HZ, Mahyuddin A, Ahmad Ghazali R, et al.
    Int J Environ Res Public Health, 2020 Jul 15;17(14).
    PMID: 32679828 DOI: 10.3390/ijerph17145107
    Sodium hypochlorite (NaOCl), an effective endodontic irrigant against Enterococcus faecalis (EF), is harmful to periapical tissues. Natural pineapple-orange eco-enzymes (M-EE) and papaya eco-enzyme (P-EE) could be potential alternatives. This study aimed to assess the antimicrobial efficacy of M-EE and P-EE at different concentrations and fermentation periods against EF, compared to 2.5% NaOCl. Fermented M-EE and P-EE (3 and 6 months) at various concentrations were mixed with EF in a 96-well plate incubated for 24 h anaerobically. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of M-EE and P-EE were determined via EF growth observation. EF inhibition was quantitatively measured and compared between different irrigants using the one-way analysis of variance (ANOVA), and different fermentation periods using the independent-samples T-test. M-EE and P-EE showed MIC at 50% and MBC at 100% concentrations. There was no significant difference in antimicrobial effect when comparing M-EE and P-EE at 50% and 100% to 2.5% NaOCl. P-EE at 6 months fermentation exhibited higher EF inhibition compared to 3 months at concentrations of 25% (p = 0.017) and 0.78% (p = 0.009). The antimicrobial properties of M-EE and P-EE, at both 100% and 50% concentrations, are comparable to 2.5% NaOCl. They could therefore be potential alternative endodontic irrigants, but further studies are required.
    Matched MeSH terms: Sodium Hypochlorite/adverse effects; Sodium Hypochlorite/pharmacology
  7. Response to: Depolarization vs. repolarization: what is the mechanism of ventricular arrhythmogenesis underlying sodium channel haploinsufficiency in mouse hearts?
    Jeevaratnam K, Guzadhur L, Goh YM, Grace AA, Huang CL
    Acta Physiol (Oxf), 2016 12;218(4):236-238.
    PMID: 27272698 DOI: 10.1111/apha.12731
    Matched MeSH terms: Sodium Channels/genetics*
  8. Using Fish Sauce as a Substitute for Sodium Chloride in Culinary Sauces and Effects on Sensory Properties
    Huynh HL, Danhi R, Yan SW
    J Food Sci, 2016 Jan;81(1):S150-5.
    PMID: 26613570 DOI: 10.1111/1750-3841.13171
    Historically, fish sauce has been a standard condiment and ingredient in various Southeast Asian cuisines. Moreover, fish sauce imparts umami taste, which may enhance perceived saltiness in food. This quality suggests that fish sauce may be used as a partial substitute for sodium chloride (NaCl) in food preparation, which may present a valuable option for health-conscious and salt-restricted consumers. However, the degree to which NaCl can be decreased in food products without compromising taste and consumer acceptance has not been determined. We hypothesized that NaCl content in food may be reduced by partial replacement with fish sauce without diminishing palatability and consumer acceptance. Preparations of 3 types of food were assessed to test this hypothesis: chicken broth (n = 72); tomato sauce (n = 73); and coconut curry (n = 70). In the first session, the percentage of NaCl that could be replaced with fish sauce without a significant change in overall taste intensity was determined for each type of food using the 2-Alternative Forced Choice method. In the second session, subjects rated 5 samples for each food with varying NaCl and/or fish sauce content on 3 sensory attributes: deliciousness; taste intensity; and saltiness. Our results demonstrate that NaCl reduction was possible in chicken broth, tomato sauce, and coconut curry at 25%, 16%, and 10%, respectively, without a significant loss (P < 0.05) in deliciousness and overall taste intensity. These results suggest that it is possible to replace NaCl in foods with fish sauce without reducing overall taste intensity and consumer acceptance.
    Matched MeSH terms: Sodium Chloride; Sodium Chloride, Dietary
  9. Fulltext Effect of frozen storage on the characteristics of a developed and commercial fish sausages
    Al-Bulushi IM, Kasapis S, Dykes GA, Al-Waili H, Guizani N, Al-Oufi H
    J Food Sci Technol, 2013 Dec;50(6):1158-64.
    PMID: 24426029 DOI: 10.1007/s13197-011-0441-x
    The effect of frozen storage on the physiochemical, chemical and microbial characteristics of two types of fish sausages was studied. Fish sausages developed (DFS) with a spice-sugar formulation and commercial fish sausages (CFS) were stored at -20 °C for 3 months. Fresh DFS contained 12.22% lipids and had a 3.53 cfu/g total bacteria count (TBC) whereas, CFS contained 5.5% lipids and had a 4.81 cfu/g TBC. During storage, TBC decreased significantly (p  0.05) in CFS. A peroxide value (PV) was not detectable until week four and eight of storage in CFS and DFS, respectively. The salt-soluble proteins (SSP) level was stable in DFS but in CFS it declined significantly (p  0.05) in both sausage types. This study showed that the effect of storage at -20 °C on fish sausages characteristics varied between formulations and depended on the ingredients of fish sausages.
    Matched MeSH terms: Sodium Chloride; Sodium Chloride, Dietary
  10. Primary recovery of a bacteriocin-like inhibitory substance derived from Pediococcus acidilactici Kp10 by an aqueous two-phase system
    Abbasiliasi S, Tan JS, Ibrahim TA, Kadkhodaei S, Ng HS, Vakhshiteh F, et al.
    Food Chem, 2014 May 15;151:93-100.
    PMID: 24423507 DOI: 10.1016/j.foodchem.2013.11.019
    A polymer-salt aqueous two-phase system (ATPS) consisting of polyethylene-glycol (PEG) with sodium citrate was developed for direct recovery of a bacteriocin-like inhibitory substance (BLIS) from a culture of Pediococcus acidilactici Kp10. The influences of phase composition, tie-line length (TLL), volume ratio (VR), crude sample loading, pH and sodium chloride (NaCl) on the partition behaviour of BLIS was investigated. Under optimum conditions of ATPS, the purification of BLIS was achieved at 26.5% PEG (8000)/11% sodium citrate with a TLL of 46.38% (w/w), VR of 1.8, and 1.8% crude load at pH 7 without the presence of NaCl. BLIS from P. acidilactici Kp10 was successfully purified by the ATPS up to 8.43-fold with a yield of 81.18%. Given that the operation of ATPS is simple, environmentally friendly and cost-effective, as it requires only salts and PEG, it may have potential for industrial applications in the recovery of BLIS from fermentation broth.
    Matched MeSH terms: Sodium Chloride/chemistry
  11. Ultrasound mediated enzymatic hydrolysis of cellulose and carboxymethyl cellulose
    Sulaiman AZ, Ajit A, Chisti Y
    Biotechnol Prog, 2013 Nov-Dec;29(6):1448-57.
    PMID: 23926080 DOI: 10.1002/btpr.1786
    A recombinant Trichoderma reesei cellulase was used for the ultrasound-mediated hydrolysis of soluble carboxymethyl cellulose (CMC) and insoluble cellulose of various particle sizes. The hydrolysis was carried out at low intensity sonication (2.4-11.8 W cm(-2) sonication power at the tip of the sonotrode) using 10, 20, and 40% duty cycles. [A duty cycle of 10%, for example, was obtained by sonicating for 1 s followed by a rest period (no sonication) of 9 s.] The reaction pH and temperature were always 4.8 and 50°C, respectively. In all cases, sonication enhanced the rate of hydrolysis relative to nonsonicated controls. The hydrolysis of CMC was characterized by Michaelis-Menten kinetics. The Michaelis-Menten parameter of the maximum reaction rate Vmax was enhanced by sonication relative to controls, but the value of the saturation constant Km was reduced. The optimal sonication conditions were found to be a 10% duty cycle and a power intensity of 11.8 W cm(-2) . Under these conditions, the maximum rate of hydrolysis of soluble CMC was nearly double relative to control. In the hydrolysis of cellulose, an increasing particle size reduced the rate of hydrolysis. At any fixed particle size, sonication at a 10% duty cycle and 11.8 W cm(-2) power intensity improved the rate of hydrolysis relative to control. Under the above mentioned optimal sonication conditions, the enzyme lost about 20% of its initial activity in 20 min. Sonication was useful in accelerating the enzyme catalyzed saccharification of cellulose.
    Matched MeSH terms: Carboxymethylcellulose Sodium/chemistry*
  12. Multi-elemental composition and physical properties of honey samples from Malaysia
    Chua LS, Abdul-Rahaman NL, Sarmidi MR, Aziz R
    Food Chem, 2012 Dec 1;135(3):880-7.
    PMID: 22953800 DOI: 10.1016/j.foodchem.2012.05.106
    The elemental profiles of six honey samples from Malaysia had been constructed using the data obtained from both ICP-AES and ICP-MS. Potassium and sodium were the most abundant minerals covering from 69.3-78.6% and 14.1-28.7%, respectively. The ratio of potassium to sodium was more than one. Even though the minerals and trace elements composition varied dependent on the type of honey samples, there was no statistically significant difference between the analysed honey samples, namely tualang, gelam, acacia and a few forest honeys based on two-factor ANOVA and cluster analysis. The total element content of honey samples were strongly correlated with the electrical conductivity, but only have moderate correlation with the ash content and honey colour based on the regression analysis. PCA result on the available elemental data from worldwide honeys, including honey samples from Malaysia revealed that potassium and sodium were the mineral markers to distinguish honey origin. Both tualang and gelam honey samples from Malaysia have close mineral profile with sesame honeys from Egypt and multifloral honeys from India, whereas forest honeys Malaysia were near to avocado honeys from Spain and multifloral honeys from India.
    Matched MeSH terms: Sodium/analysis
  13. Fulltext Effect of accelerator in green synthesis of silver nanoparticles
    Darroudi M, Ahmad MB, Abdullah AH, Ibrahim NA, Shameli K
    Int J Mol Sci, 2010;11(10):3898-905.
    PMID: 21152307 DOI: 10.3390/ijms11103898
    Silver nanoparticles (Ag-NPs) were successfully synthesized in the natural polymeric matrix. Silver nitrate, gelatin, glucose, and sodium hydroxide have been used as silver precursor, stabilizer, reducing agent, and accelerator reagent, respectively. This study investigated the role of NaOH as the accelerator. The resultant products have been confirmed to be Ag-NPs using powder X-ray diffraction (PXRD), UV-vis spectroscopy, and transmission electron microscopy (TEM). The colloidal sols of Ag-NPs obtained at different volumes of NaOH show strong and different surface plasmon resonance (SPR) peaks, which can be explained from the TEM images of Ag-NPs and their particle size distribution. Compared with other synthetic methods, this work is green, rapid, and simple to use. The newly prepared Ag-NPs may have many potential applications in chemical and biological industries.
    Matched MeSH terms: Sodium Hydroxide/chemistry
  14. Subcritical water liquefaction of oil palm fruit press fiber for the production of bio-oil: effect of catalysts
    Mazaheri H, Lee KT, Bhatia S, Mohamed AR
    Bioresour Technol, 2010 Jan;101(2):745-51.
    PMID: 19740652 DOI: 10.1016/j.biortech.2009.08.042
    Decomposition of oil palm fruit press fiber (FPF) to various liquid products in subcritical water was investigated using a high-pressure autoclave reactor with and without the presence of catalyst. When the reaction was carried in the absence of catalyst, the conversion of solid to liquid products increased from 54.9% at 483 K to 75.8% at 603 K. Simultaneously, the liquid yield increased from 28.8% to 39.1%. The liquid products were sub-categorized to bio-oil (benzene soluble, diethylether soluble, acetone soluble) and water soluble. When 10% ZnCl(2) was added, the conversion increased slightly but gaseous products increased significantly. However, when 10% Na(2)CO(3) and 10% NaOH were added independently, the solid conversion increased to almost 90%. In the presence of catalyst, the liquid products were mainly bio-oil compounds. Although solid conversion increased at higher reaction temperature, but the liquid yield did not increase at higher temperature.
    Matched MeSH terms: Sodium Hydroxide/chemistry
  15. Fulltext Synthesis and characterization of novel dimeric ionic liquids by conventional approaches
    Ganesan K, Alias Y
    Int J Mol Sci, 2008 Jun;9(7):1207-13.
    PMID: 19325800 DOI: 10.3390/ijms9071207
    The (1)H-NMR shifts of the imidazolium protons of some novel dimeric ionic liquids were examined in various deuterated solvents. Interactions between the solvent and the imidazolium salt of butyl substituted ionic liquids were observed to give higher chemical shifts than methyl substitution.
    Matched MeSH terms: Sodium Chloride; Sodium Chloride, Dietary
  16. Fulltext Improvement of halophilic cellulase production from locally isolated fungal strain
    Gunny AA, Arbain D, Jamal P, Gumba RE
    Saudi J Biol Sci, 2015 Jul;22(4):476-83.
    PMID: 26150755 DOI: 10.1016/j.sjbs.2014.11.021
    Halophilic cellulases from the newly isolated fungus, Aspergillus terreus UniMAP AA-6 were found to be useful for in situ saccharification of ionic liquids treated lignocelluloses. Efforts have been taken to improve the enzyme production through statistical optimization approach namely Plackett-Burman design and the Face Centered Central Composite Design (FCCCD). Plackett-Burman experimental design was used to screen the medium components and process conditions. It was found that carboxymethylcellulose (CMC), FeSO4·7H2O, NaCl, MgSO4·7H2O, peptone, agitation speed and inoculum size significantly influence the production of halophilic cellulase. On the other hand, KH2PO4, KOH, yeast extract and temperature had a negative effect on enzyme production. Further optimization through FCCCD revealed that the optimization approach improved halophilic cellulase production from 0.029 U/ml to 0.0625 U/ml, which was approximately 2.2-times greater than before optimization.
    Matched MeSH terms: Carboxymethylcellulose Sodium; Sodium Chloride
  17. Fulltext Survey of availability of iodine-enriched salt in Sarawak
    Taha AM, Zainab T, Lau D, Yeo P
    Med J Malaysia, 1995 Dec;50(4):391-5.
    PMID: 8668062
    Three hundred and forty five salt samples were randomly taken from 106 sources where iodised salts were supplied or put for sale in all areas gazetted as endemic goitre areas in Sarawak. The samples were analysed for the presence of iodine. In areas in Sibu, Sarikei and Kapit Divisions, 53-70% of salt put for sale were iodised while in the other 6 Divisions, it was less than 27%. As iodisation of salt is an interventive measure in addressing the goitre problem in the State, regular monitoring of iodisation facilities and iodine content of iodised salt in the affected areas is important to ensure the effectiveness of the programme.
    Matched MeSH terms: Sodium Chloride, Dietary/administration & dosage*
  18. Validation and comparison of three formulae to estimate sodium and potassium excretion from a single morning fasting urine compared to 24-h measures in 11 countries
    Mente A, O'Donnell MJ, Dagenais G, Wielgosz A, Lear SA, McQueen MJ, et al.
    J Hypertens, 2014 May;32(5):1005-14; discussion 1015.
    PMID: 24569420 DOI: 10.1097/HJH.0000000000000122
    Although 24-h urinary measure to estimate sodium and potassium excretion is the gold standard, it is not practical for large studies. We compared estimates of 24-h sodium and potassium excretion from a single morning fasting urine (MFU) using three different formulae in healthy individuals.
    Matched MeSH terms: Sodium/urine*
  19. Fulltext Synthesis, Characterization and the Solvent Effects on Interfacial Phenomena of Jatropha Curcas Oil Based Non-Isocyanate Polyurethane
    Haniffa MACM, Ching YC, Chuah CH, Kuan YC, Liu DS, Liou NS
    Polymers (Basel), 2017 May 01;9(5).
    PMID: 30970841 DOI: 10.3390/polym9050162
    Non-isocyanate polyurethane (NIPU) was prepared from Jatropha curcas oil (JCO) and its alkyd resin via curing with different diamines. The isocyanate-free approach is a green chemistry route, wherein carbon dioxide conversion plays a major role in NIPU preparation. Catalytic carbon dioxide fixation can be achieved through carbonation of epoxidized derivatives of JCO. In this study, 1,3-diaminopropane (DM) and isophorone diamine (IPDA) were used as curing agents separately. Cyclic carbonate conversion was catalyzed by tetrabutylammonium bromide. After epoxy conversion, carbonated JCO (CJCO) and carbonated alkyd resin (CC-AR) with carbonate contents of 24.9 and 20.2 wt %, respectively, were obtained. The molecular weight of CJCO and CC-AR were determined by gel permeation chromatography. JCO carbonates were cured with different amine contents. CJCO was blended with different weight ratios of CC-AR to improve its characteristics. The cured NIPU film was characterized by spectroscopic techniques, differential scanning calorimetry, and a universal testing machine. Field emission scanning electron microscopy was used to analyze the morphology of the NIPU film before and after solvent treatment. The solvent effects on the NIPU film interfacial surface were investigated with water, 30% ethanol, methyl ethyl ketone, 10% HCl, 10% NaCl, and 5% NaOH. NIPU based on CCJO and CC-AR (ratio of 1:3) with IPDA crosslink exhibits high glass transition temperature (44 °C), better solvent and chemical resistance, and Young's modulus (680 MPa) compared with the blend crosslinked with DM. Thus, this study showed that the presence of CC-AR in CJCO-based NIPU can improve the thermomechanical and chemical resistance performance of the NIPU film via a green technology approach.
    Matched MeSH terms: Sodium Chloride; Sodium Hydroxide
  20. Fulltext Hydrazinium 2-amino-4-nitro-benzoate dihydrate: crystal structure and Hirshfeld surface analysis
    Wardell JL, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2017 Apr 01;73(Pt 4):579-585.
    PMID: 28435725 DOI: 10.1107/S2056989017004352
    In the anion of the title salt hydrate, H5N2(+)·C7H5N2O4(-)·2H2O, the carboxyl-ate and nitro groups lie out of the plane of the benzene ring to which they are bound [dihedral angles = 18.80 (10) and 8.04 (9)°, respectively], and as these groups are conrotatory, the dihedral angle between them is 26.73 (15)°. An intra-molecular amino-N-H⋯O(carboxyl-ate) hydrogen bond is noted. The main feature of the crystal packing is the formation of a supra-molecular chain along the b axis, with a zigzag topology, sustained by charge-assisted water-O-H⋯O(carboxyl-ate) hydrogen bonds and comprising alternating twelve-membered {⋯OCO⋯HOH}2 and eight-membered {⋯O⋯HOH}2 synthons. Each ammonium-N-H atom forms a charge-assisted hydrogen bond to a water mol-ecule and, in addition, one of these forms a hydrogen bond with a nitro-O atom. The amine-N-H atoms form hydrogen bonds to carboxyl-ate-O and water-O atoms, and the amine N atom accepts a hydrogen bond from an amino-H atom. The hydrogen bonds lead to a three-dimensional architecture. An analysis of the Hirshfeld surface highlights the major contribution of O⋯H/H⋯O hydrogen bonding to the overall surface, i.e. 46.8%, compared with H⋯H contacts (32.4%).
    Matched MeSH terms: Sodium Chloride; Sodium Chloride, Dietary
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